The demonstration is set for 3 p.m. in McKeldin Square near the Inner Harbor. That's about two hours before the scheduled start of the Preakness Stakes horse race at Pimlico Race Course, 5 1/2 miles away.

Sharon Black of the Baltimore People's Power Assembly says marchers from the rally are unlikely to reach Pimlico.

They're seeking amnesty for the nearly 500 people police say they arrested from April 23 to May 3. The civil unrest followed Gray's death April 19 from a spinal injury he sustained in police custody.

Speakers will include the Rev. Cortly "C.D." Witherspoon, president of the Southern Christian Leadership Conference's Baltimore chapter.